What plants live here?
Noxious Weeds are everyone’s problem!
Plants are an essential part of our lives. They make the oxygen we breathe and the food we eat. Plants also add
color and beauty to our home and yards. We couldn’t get along without them! But some plants can cause problems.
People have brought plants to Oregon from other parts of the world, neighboring states, or from other regions in
Oregon. Sometimes people brought them here on purpose because they were pretty or offered some medicinal use.
Other plants arrived accidentally. Some of these plants arrived without any natural enemies, like insects or competing
native vegetation, to help keep them under control. In some cases, these introduced plants have spread wildly and
caused big problems. We call these plants noxious weeds.
Noxious weeds affect everyone in Oregon. They compete with crops by decreasing the amount of food that farmers
can grow. They also cause farmers to spray herbicides to get rid of the weeds that compete with their crops; this
can have a harmful effect on wildlife, aquatic organisms, human health, and water quality. Some noxious weeds are
poisonous to people and animals. Noxious weeds can also crowd out native plants, which harms wildlife and livestock that
depend on native plants for nourishment. Lakes and streams are also affected by noxious weeds. In some places, noxious
weeds grow so thickly that people can no longer go swimming, fishing, or boating.
YOU CAN HELP STOP NOXIOUS WEEDS! Learn what plants cause problems and be careful not to spread
them. Don’t plant noxious weeds – help your parents choose pretty native plants for your yard. Check your
clothing, shoes, pets, bike/ATV tires, and family boat or car for noxious weed “hitchhikers.” With these simple steps
you can help protect Oregon from the harmful effects of noxious weeds!
What noxious weeds have you seen in your
neighborhood?
Because of its beautiful pinkish purple flowers, purple loosestrife was brought here from Eurasia for its use as a garden plant. However,
loosestrife has escaped gardens to become a big problem in wetlands. Purple loosestrife crowds out native wetland plants and destroys wildlife
habitat. It can also clog up waterways and degrade water quality.
Scotch thistle is a native of Europe and eastern Asia and is probably an escaped ornamental. Its flowers are numerous, spiny, rounded on the
bottom but flat on top, and pale purple to violet in color. They stand alone on branch tips. Scotch thistle stands are dense andpractically
impenetrable due to the weed's spiny nature and large size. It spreads by seed and generally inhabits moist sites or drainages in dry locations.
A native of southern Europe, yellow starthistle probably arrive herein soil carried on ships. Yellow starthistle crowds out our native plants and
other beneficial plants that animals depend on for food. Yellow starthistle also has sharp spines that can hurt people and animals. This plant is
particularly harmful for horses because it causes chewing disease, which can kill them.
Puncturevine has yellow flowers and is a thoroughly naturalized invader from Europe. It spreads by seed and is most often found
on sandy, dry, or gravely sites. Puncturevine produces sharply pointed burs that stick painfully in bare feet and cause bicycle
flats, reducing the recreational potential of many areas. Even light truck tires can be punctured by seeds.
Leafy spurge was brought to the U.S. from Eurasia about 1897. A milky latex exists in all parts of the plant that can produce blisters and dermatitis
in humans, cattle, and horses and may cause permanent blindness if rubbed into the eye. Protection is need when handling leafy spurge. It spreads both
by seed and creeping roots and grows in many environmental conditions.
Diffuse knapweed is a native of Eurasia, introduced into the U.S. in the early 1900s. It spreads by seed, aided by the tumbling of windblown mature plants,
and it grows under a wide range of conditions. Diffuse knapweed has white or light pink flowers and is a very aggressive species that can infest large areas
quickly. The species has little value as forage for cattle and limited seasonal value for big game. Knapweed infestations increase production costs for
ranchers, impair the quality of wildlife habitat, decrease plant diversity, increase soil erosion rates, decrease the visual quality and appeal of recreational
lands, and pose wildfire hazards.
A native of Eurasia, Dalmatian toadflax was brought here for use as a garden plant because of its yellow flowers. However, this species can be a
big problem. Dalmatian toadflax crowds out our native plants and other beneficial plants that animals depend on for food. In addition, many animals
don’t like the taste of Dalmatian toadflax.
What are Native Plants?
Native plants are those that evolved naturally in North America. More specifically, native plants in a particular area
are those that were growing naturally in the area before humans introduced plants from distant places. In North
America, native plants typically grow in communities with species adapted to similar soil, moisture, and weather
conditions. Some of the widespread communities in Eastern Oregon include coniferous forests and sagebrush steppe, and
freshwater wetlands and riparian areas.
Native plants convert the sun’s energy into food and therefore they are the source of all food to the animal kingdom.
Native plants cycle and clean fresh water and ensure soil stability for the environment. We depend on plants to
provide the oxygen that all living things require.
Native plant communities provide habitat for several thousand plant and animal species. Many of these animals and
insects are uncommon in Oregon and are almost completely dependent on native plant communities for their survival.
Native plant communities have also played an important role in the development of Oregon’s cultural history and
heritage. For several thousand years, human lives have been closely connected with the resources available for plants
– which have been sources of food, shelter, clothing, fuel, and medicine. In the last 150-200 years, native plant
products have been a sustainable source of economic wealth.
The beauty of wildflowers is just one of the many values of native plants. They provide recreational experiences for
hunters, anglers, hikers, campers, bird watchers, and other nature lovers.
Decisions made by YOU today are likely to determine whether Oregon’s native plant communities will exist for future
generations. The key to protecting native plants is awareness of their location, value, and finding ways to avoid
destroying them.
YOU CAN MAKE A DIFFERENCE!
Many species of lupine grace the sagebrush steppe, ranging in color from cream to purple to blue. Their grape-cluster flowers and
fruiting seedpods identify them as members of the pea family. Lupines contribute to soil health by fixing nitrogen. Landowners who want to
encourage their spread must remove competing colonies of knapweed, which are toxic to lupines and many other native plants.
Yarrow grows at different elevations throughout Oregon being common along dry roadsides and open meadows. The leaves of yarrow
are finely dissected like a feather and can be mistaken for fern leaves. Yarrow leaves have a strong odor when crushed. The small
white flowers occur in heads that bloom from June to August depending on the elevation.
Sulfur buckwheat is found on rocky exposures, these bright golden flowers may cover entire slopes with vivid color. However, their flower color can vary from
dull yellow to cream colored blossoms. The flowers are tightly clustered into an umbrella-like head. Their stems grow a woody base and bear small silverygreen leaves arranged in whorls. Clumps of sulfur buckwheat occupy crevices and cracks where one would not expect plants to survive.
The deep blue flowers of the larkspur are easy to recognize, some species are cultivated in gardens. The flower has always been the
subject of ill will with the rancher, however, because it is poisonous to cattle. The young shoots in spring are considered to be especially
toxic. Domestic sheet do not seem to be affected by the larkspur. The larkspur’s beauty cannot be disputed and a hillside covered with
these flowers is a sight to remember. You can recognize a larkspur by the divided leaves and odd-shaped flowers which have 5 blue or purple
flowerlike sepals with the upper one spurred backwards.
Also called cat’s ear. The name cat’s ear reflects the soft, hairy inner surfaces of the three petals that form the cup-shaped flowers.
This native plant is abundant in the sagebrush steppe in Eastern Oregon. This plant is highly palatable to livestock and can easily be
eliminated from heavily grazed areas. The leaves are grass-like becoming rolled at the tip. The flowers are showy and erect. Each white
petal has a longitudinal green stripe with an angled reddish-purple band.
Compiled by Umatilla County Soil and Water Conservation District
with materials from:
Celebrating Wildflowers, by Karl Urban and other Federal Agencies
The Weed Coloring Book, from Washington State Noxious Weed Control Board
Who Lives Here? The Natives or the Noxious?
Various noxious weed and native plant informational websites.